Genetic control of lactate dehydrogenase formation in the hagfish Eptatretus stoutii

The isozyme patterns of lactate dehydrogenases of various tissues were studied on 51 hagfish by starch-gel electrophoresis. Nine lactate dehydrogenase phenotypes were encountered, suggesting the coexistence of two alleles at each of the two separate gene loci. There apparently was no interaction between the products of these two separate loci. Even the products of two alleles at the same locus were apparently incapable of forming hybrid molecules, an indication of the possible monomeric nature of each lactate dehydrogenase molecule.

Multiple gene loci for the monomeric hemoglobin of the hagfish (Eptatretus stoutii)

The fact that members of the subclass Cyclotomata possess monomeric hemoglobin molecules has been known for some time. Electrophoresis of hemolysates from 12 hagfish (Eptatretus stoutii) revealed five hemoglobin phenotypes with four to six distinct zones of hemoglobin. Each zone is believed to represent a monomer containing one heme group on a single polypeptide chain with a molecular weight of approximately 18,000. It is postulated that these monomers are controlled by genes at four loci.

Hexose-6-phosphate dehydrogenase found in human liver

Starch-gel electrophoresis of extracts of human liver revealed the presence of a new hexose-6-phosphate dehydrogenase that was slower-moving at pH 8.6 than the sex-linked glucose-6-phosphate dehydrogenase. When the gel plate was stained, galactose-6-phos phate being used as a substrate, this enzyme band stained intensely, but the sex-linked glucose-6-phosphate dehydro genase failed to stain. This new human enzyme may well be homologous with the autosomally inherited glucose-6-phosphate dehydrogenase of the deer mouse (Peromyscus maniculatus), re ported by Shaw and Barto.

Intraindividual chromosomal polymorphism in green sunfish (Lepomis cyanellus) as evidence of somatic segregation

Of 30 adult specimens of green sunfish, <i>Lepomis cyanellus</i>, obtained from a fish farm in southern California, 16 were heterozygous for a single Robertsonian translocation while 12 carried no translocation; the remaining two were homozygous for a translocation. In each heterozygote, the three cell types coexisted: the original heterozygous set (2n = 47, one metacentric) and the two homozygous sets (2n = 48, no metacentric, and 2n = 46, two metacentrics). No intraindividual chromosomal polymorphism was evident in those specimens which carried no translocation as well as in those which were homozygous for a translocation.